Road hazards can often make driving on roads unsafe. Although some road hazards may be avoided, some may not. It is often difficult for a driver to assess a proper means of traversing an unavoidable road hazard. For example, the driver may not have sufficient experience with driving in snow to determine a safe traveling speed. Furthermore, some road hazards, such as black ice, may be undetectable by even an experienced driver. Notification of a hazard in time to take suitable evasive action and avoid a crash is an essential part of safe driving.